"Men love their spouses, but they don't know how to fix their relationship problems, so they go outside their marriages to fill any holes," says licensed marriage and family therapist Susan Mandel, PhD. Men want it all and have the skewed notion that another woman will make the longing for something more disappear. Then, they can live happily ever after with their wife--and their mistress--without confronting the real issues.

Fact #4: Men hate themselves after affairs.

You may think of cheaters as men without morals, but while they may like what they did, they tend to despise themselves after their indiscretions. "If he puts his ego to the side, he'll feel like a piece of garbage," says relationship expert Charles J. Orlando, author of The Problem with Women...Is Men. "After all, he's betraying another human being who he claims to care about, so that takes its toll on every part of his psyche." A cheater can feel as though he's failed as a man.